Food poisoning usually isn’t life threatening. It can be uncomfortable, but most people recover completely within a few days, even without treatment.
Foodborne illness, typically known as food poisoning, results from eating contaminated, spoiled, or toxic food. The most common symptoms of food poisoning are nausea, vomiting, and diarrhea.
Although it’s quite uncomfortable, food poisoning isn’t unusual. According to the
If you have food poisoning, chances are it won’t go undetected. The symptoms can vary depending on the source of the infection.
A case of food poisoning will typically involve a few of the following symptoms:
- abdominal cramps
- diarrhea
- nausea
- vomiting
- loss of appetite
- mild fever
- weakness
- headache
Symptoms of potentially life threatening food poisoning include:
- diarrhea that lasts for more than 3 days
- a fever higher than
102°F (38.9°C) - difficulty seeing or speaking
- symptoms of severe dehydration, such as:
- dry mouth
- little to no urine output
- difficulty keeping fluids down
- bloody urine
If you experience any of these symptoms, contact a doctor or seek medical treatment immediately.
How long does food poisoning last?
The length of time it takes for symptoms to appear depends on the source of the infection, but it can range from
With or without treatment, most cases will resolve within 1 week.
Most food poisoning can be traced to one of three major causes:
- bacteria
- parasites
- viruses
These pathogens can be found on almost all food humans eat. However, heat from cooking usually kills the pathogens before the food reaches your plate. Foods eaten raw are common sources of food poisoning because they don’t go through the cooking process.
Occasionally, food comes into contact with organisms from fecal matter or vomit. This is most likely to happen when someone who is ill prepares food without washing their hands first.
Some frequently contaminated foods are:
- meat
- eggs
- dairy
- water
Bacteria
Bacteria are by far the most common cause of food poisoning. Bacterial causes of food poisoning include:
- E. coli — in particular, Shiga toxin-producing E. coli (STEC)
- Listeria monocytogenes
- Salmonella
- Campylobacter
- Clostridium botulinum
- Staphylococcus aureus
- Shigella
- Vibrio vulnificus
When you think of dangerous bacteria, names such as “E. coli” and “Salmonella” likely come to mind — and for a good reason.
Salmonella is
Parasites
Food poisoning caused by parasites isn’t as common as food poisoning caused by bacteria, but parasites that spread through food are still very dangerous. They include:
- Toxoplasma gondii
- Giardia lamblia
- various tapeworms, such as:
- Taenia saginata (beef tapeworm)
- Taenia solium (pork tapeworm)
- Diphyllobothrium latum (fish tapeworm)
- Cryptosporidium
- Ascaris lumbricoides, a type of roundworm
- flukes (flatworms), such as Opisthorchiidae (liver fluke) and Paragonimus (lung fluke)
- pinworms, or Enterobiasis
- Trichinella
According to the
Parasites can live in your digestive tract and may go undetected for years. Pregnant people and those with weakened immune systems are at risk of more serious side effects if certain parasites take up residence in their intestines.
Viruses
Food poisoning can also be caused by a virus, such as:
- norovirus, which is sometimes known as the Norwalk virus
- rotavirus
- astrovirus
- sapovirus
- hepatitis A virus
The norovirus causes 19 million to 21 million cases of vomiting and diarrhea in the United States each year. In rare cases, it can be fatal. Other viruses cause similar symptoms but are less common.
| Cause of food poisoning | How soon symptoms start (after exposure) | Where it’s found or how it’s transmitted |
|---|---|---|
| Ascaris lumbricoides | rarely causes noticeable symptoms | produce grown in contaminated soil |
| astrovirus | 4 to 5 days | contaminated water |
| Campylobacter | • raw or undercooked chicken • unpasteurized milk • contaminated water | |
| Clostridium botulinum | • preserved vegetables that are low in acid (such as green beans and mushrooms) • canned tuna • fermented fish • ham • sausage • pruno (“prison wine”) • items that have been improperly canned or bottled at home | |
| Cryptosporidium | • fresh fruits • fruit juice • fresh vegetables • unpasteurized apple cider • unpasteurized milk • contaminated water | |
| Diphyllobothrium latum (fish tapeworm) | rarely causes noticeable symptoms | raw or undercooked fish |
| E. coli | • raw or undercooked beef • raw lettuce and other vegetables • raw sprouts • unpasteurized milk • contaminated water | |
| Enterobiasis (pinworms) | rarely causes noticeable symptoms | • mostly transmitted by contact with a contaminated surface or close contact a person who has a case • can also be caused by improper food handling |
| Giardia lamblia | • produce grown in contaminated soil • contaminated meat • contaminated water • can also be caused by improper food handling | |
| hepatitis A virus | • frozen berries • frozen vegetables • undercooked shellfish • contaminated water • can also be caused by improper food handling | |
| Listeria monocytogenes | • unpasteurized dairy products (such as milk and soft cheeses) • melon • raw sprouts • deli meat • smoked fish | |
| norovirus | • oysters and other shellfish • lettuce and other leafy greens • fresh fruit • contaminated water • can also be caused by improper food handling | |
| Opisthorchiidae (liver fluke) | raw or undercooked crab, crawfish, or fish | |
| Paragonimus (lung fluke) | raw, undercooked, pickled, or salted crab or crawfish | |
| rotavirus | • shellfish • salads • contaminated ice | |
| Salmonella | • raw or undercooked poultry • eggs • raw fruits and vegetables • contaminated water | |
| sapovirus | • oysters • clams • contaminated water | |
| Shigella | usually 1 to 2 days (but can take up to 7 days) | • raw vegetables • cold salads such as tuna salad and potato salad • sandwiches • contaminated water • can also be caused by improper food handling |
| Staphylococcus aureus | • puddings • cream-filled baked goods • sliced meats • cold salads such as tuna salad and potato salad • sandwiches • can also be caused by improper food handling or leaving foods at improper temperatures | |
| Taenia saginata (beef tapeworm) | rarely causes noticeable symptoms | raw or undercooked beef |
| Taenia solium (pork tapeworm) | rarely causes noticeable symptoms | raw or undercooked pork |
| Toxoplasma gondii | rarely causes noticeable symptoms | • undercooked shellfish or meat (specifically pork, lamb, and venison) • contaminated water • mostly transmitted through contact with infected cat feces but can also be caused by improper food handling or preparation |
| Trichinella | • • 2 to 15 days for other symptoms | raw or undercooked meat (specifically pork and wild game) |
| Vibrio vulnificus | raw or undercooked shellfish, especially oysters |
Food poisoning can usually be treated at home. Here are some ways you can help treat food poisoning:
Stay hydrated
If you have food poisoning, it’s crucial to stay properly hydrated. Sports drinks that are high in electrolytes can be helpful. Fruit juice and coconut water can restore carbohydrates and help with fatigue.
Try to avoid caffeine, which may irritate your digestive tract. Decaffeinated teas made with soothing herbs may help calm an upset stomach. Examples include:
- chamomile
- peppermint
- dandelion
Read about more remedies for an upset stomach.
Take over-the-counter (OTC) medications
OTC medications such as loperamide (Imodium) and Pepto-Bismol can help you manage diarrhea and suppress nausea.
Pyrantel pamoate (Reese’s Pinworm Medicine) is a common remedy for pinworms.
However, you should check with a doctor before using these medications because your body uses vomiting and diarrhea to get rid of the toxin. Also, using these medications could mask the severity of your condition and cause you to delay seeking expert treatment.
Take prescription medications
Although many cases of food poisoning clear up on their own, you may benefit from prescription medications, depending on the pathogen responsible for your condition.
Prescription medications may be helpful if you are older, immunocompromised, or pregnant. Antibiotic treatment can help prevent an infection from transmitting to your unborn baby.
If you need prescription medications, a doctor may recommend the following medications for certain causes of foodborne illness:
- A. lumbricoides: the antiparasitic medications albendazole (Albenza) or mebendazole (Enverm)
- Campylobacter: the antibiotic azithromycin (Zithromax)
- Cryptosporidium: the antiparasitic medication nitazoxanide (Alinia), which is used to treat diarrhea
- D. latum (fish tapeworm): the antiparasitic medication praziquantel (Biltricide)
- Enterobiasis (pinworms): albendazole (Albenza) or mebendazole (Enverm)
- G. lamblia:
- nitazoxanide (Alinia)
- the antibiotics metronidazole (Flagyl), paromomycin, quinacrine, or furazolidone
- the antibiotic and antiparasitic medication tinidazole (Tindamax)
- L. monocytogenes: the antibiotic ampicillin
- Opisthorchiidae (liver fluke): praziquantel (Biltricide) or albendazole (Albenza)
- Paragonimus (lung fluke): praziquantel (Biltricide) or the antiparasitic medication triclabendazole (Egaten)
- Shigella: the antibiotics azithromycin (Zithromax) or ciprofloxacin (Cipro)
- T. saginata (beef tapeworm): praziquantel (Biltricide) or albendazole (Albenza), which are off-label treatments
- T. solium (pork tapeworm): praziquantel (Biltricide) or albendazole (Albenza), which are off-label treatments
- T. gondii:
- a combination of the antiparasitic medication pyrimethamine (Daraprim) and an antibiotic such as sulfadiazine
- the antibiotic spiramycin, as a stand-alone medication
- Trichinella: albendazole (Albenza) or mebendazole (Enverm)
OFF-LABEL DRUG USEOff-label drug use means a drug that’s approved by the Food and Drug Administration (FDA) for one purpose is used for a different purpose that hasn’t yet been approved.
However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing and approval of drugs but not how doctors use drugs to treat their patients. So a doctor can prescribe a drug however they think is best for your care.
Receive an antitoxin
An infection with C. botulinum is considered a medical emergency. Seek medical care as soon as you can.
If you have a case of C. botulinum, a doctor will administer an antitoxin. Babies will receive a special antitoxin called BabyBIG (botulism immune globulin).
Rest
It’s important to get plenty of rest when you’re recovering from food poisoning.
Seek treatment for severe cases
In severe cases of food poisoning, you may need hydration with intravenous (IV) fluids at a hospital.
In the very worst cases of food poisoning, a longer hospital stay may be required while you recover. Severe cases of C. botulinum, which are rare, may even require mechanical ventilation.
It’s best to avoid solid foods until diarrhea and vomiting have passed. Instead, ease back into your regular diet by eating or drinking easy-to-digest foods that are bland and low in fat, such as:
- saltine crackers
- toast
- gelatin
- bananas
- rice
- oatmeal
- bland potatoes
- boiled vegetables
- chicken broth
- soda without caffeine, such as ginger ale or root beer
- diluted fruit juices
- sports drinks
To prevent your stomach from getting more upset, try to avoid the following harder-to-digest foods, even if you think you feel better:
- dairy products, especially milk and cheese
- fatty foods
- fried foods
- highly seasoned foods
- foods that are high in sugar
- spicy foods
Also avoid:
- caffeine
- alcohol
- nicotine
A doctor may be able to determine which type of food poisoning you have based on your symptoms.
In severe cases, healthcare professionals may perform blood tests, stool tests, and tests on food that you’ve eaten to find out what’s responsible for your food poisoning. A doctor may also use a urine test to evaluate whether you are dehydrated due to food poisoning.
If you need help finding a primary care doctor, check out our FindCare tool here.
Anyone can contract food poisoning. Statistically speaking, nearly everyone will experience food poisoning at least once in their lives.
Some populations are more at risk than others, including:
- Immunocompromised people: Anyone with a suppressed immune system or an autoimmune disease may have a greater risk of infection and complications resulting from food poisoning.
- Pregnant people: Pregnant people are more at risk because their bodies are coping with changes to their metabolism and circulatory system during pregnancy.
- Older adults: Adults 65 years old or older are at a greater risk of contracting food poisoning because their immune systems may not respond quickly to infectious organisms.
- Young children: Children under 5 years old are also considered an at-risk population because their immune systems aren’t as developed as those of adults. Young children are more easily affected by dehydration from vomiting and diarrhea.
The best way to prevent food poisoning is to handle your food safely and avoid any food that may be unsafe.
Some foods are more likely to cause food poisoning because of how they’re produced and prepared. Infectious agents that are killed during cooking may be present in certain foods, such as:
- meat
- poultry
- eggs
- shellfish
Food poisoning can occur if these foods are eaten in their raw form if they are not cooked properly, or if people don’t properly clean their hands and other surfaces that have had contact with the food.
Other foods that are likely to cause food poisoning include:
- sushi and other fish products that are served raw or undercooked
- deli meats and hot dogs that aren’t heated or cooked
- ground beef, which may contain meat from several animals
- unpasteurized milk, cheese, and juice
- raw, unwashed fruits and vegetables
To try to avoid food poisoning, take these steps:
- Always wash your hands before cooking or eating food.
- Make sure your food is properly sealed and stored.
- Thoroughly cook meat and eggs.
- Sanitize any surface or utensil that comes into contact with raw foods before using it to prepare other foods.
- Make sure to wash fruits and vegetables before serving them.
It’s extremely rare for food poisoning to be life threatening. While having food poisoning is quite uncomfortable, the good news is that most people recover completely within a few days, even without treatment.
What’s the difference between food poisoning and a stomach bug?
Food poisoning typically starts to cause symptoms, such as diarrhea or vomiting, within 3 to 6 hours after you’ve eaten something. The stomach flu takes longer to cause symptoms — typically 12 to 24 hours.
Millions of people get food poisoning every year. Many cases of bacterial, viral, or parasitic food poisoning are treatable, and food poisoning very rarely requires serious medical attention.
You can take certain steps to prevent food poisoning, such as washing your hands before preparing meals and avoiding raw or undercooked meat, poultry, eggs, and shellfish.
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